Electroluminescent organic light-emitting diodes, a new generation of display devices have gained popular attention due to their self-luminescence, rapid response, wide angle of view, possible fabrication into a flexible display screen, and other unique characteristics. Organic Light-Emitting Diodes (OLEDs) which are current-driven active light-emitting display devices can be categorized into Passive Matrix-Organic Light-Emitting Diodes (PM-OLEDs) and Active Matrix-Organic Light-Emitting Diodes (AM-OLEDs), dependent upon their driver modes. Instantaneous high current required in a passive driver mode may come with high power consumption, low efficiency, and other drawbacks, and these drawbacks can be overcome with the AM-OLEDs which display a high resolution with low power consumption.
In the AM-OLEDs, organic light-emitting diodes are driven using thin film transistors, which are made of polysilicon at low temperature, to emit light. However a forward transfer characteristic and a reverse transfer characteristic of a thin film transistor (TFT) may have a hysteresis, so that the luminance presented on a pixel when switched from a dark state to a bright state may not be the same as the luminance presented on the pixel being switched from a bright state to a dark state at the same grayscale. The forward transfer characteristic and the reverse transfer characteristic may be significantly different from each other particularly in a range of mid-low grayscales, that is, when the pixel is switched from a dark state to some mid-low grayscale, or from a bright state to the same mid-low grayscale, then an afterimage of a preceding frame of image may appear in a switched picture despite the same data signal, input to the pixel, corresponding to the mid-low grayscale.